No description available.

Among 29 strains of bifidobacteria studied as sources of beta-galactosidase enzyme, Bifidobacterium infantis HL96 showed the highest hydrolytic and transgalactosylic activities. This strain grew well in a MRS medium containing various sugars including lactose, and produced three beta-galactosidases (termed beta-Gal I, II, III). / Two genes, beta-galI and beta-galIII, located on 4.6 and 4.4 kb DNA fragments respectively, were cloned into E. coli, and the nucleotide sequences were determined. The 3,069 by-long beta-galI, encoded a polypeptide with a Mr of 113 kDa. A putative ribosome-binding site and a promoter sequence were recognized at the 5' flanking region of beta-galI. A partial sequence of an ORF transcribing divergently from beta-galI resembled a lactose permease gene. The beta-galIII gene, which is 2,076 bp long, encoded a polypeptide with a Mr of 76 kDa. A rho-independent, transcription terminator-like sequence was found 25 bp downstream of the termination codon. / The amino acid sequences of beta-GalI and beta-GalIII were homologous to those in the LacZ and LacG families, respectively. The acid-base, nucleophilic, and substrate recognition sites conserved in the LacZ family were found in beta-GalI, and a possible acid-base site proposed for the LacG family was located in beta-GalIII, containing a glutamate at residue 160. beta-GalI and beta-GalIII were over-expressed 35 and 96 times respectively in E. coli by using a pET expression system. / Both beta-GalI and beta-GalIII were specific for beta-D -anomeric linked galactosides, but beta-GalI showed more hydrolytic and synthetic activities toward lactose than beta-GalIII. The galacto-oligosaccharides (GaOS) production mediated by beta-GalI at 37°C in 20% (w/v) lactose was 130 mg/ml, which is six times higher than that of beta-GalIII. The yield of GaOS further increased to 190 mg/ml in 30% (w/v) lactose. A major tri-saccharide produced by beta-GalI was characterized as O-beta- D-galactopyranosyl-(1-3)-O-beta-D-galactopyranosyl-(1-4)- D-glucopyranose. / beta-GalI was purified by ammonium sulphate precipitation, and anion-exchange (Mono-Q) and gel filtration (Superose 12) chromatographic steps. The enzyme appeared to be a tetramer, with a Mr of 470 kDa as estimated by native PAGE and gel-filtration chromatography. The optimum temperature and pH for ONPG and lactose as substrates were 60°C, pH 7.5, and 50°C, pH 7.5, respectively. The enzyme was stable over the pH range of 5~8.5, and was particularly active at 50°C for more than 80 min. The enzyme was significantly activated by reducing agents, especially glutathione, as well as by Na+ and K+ cations. Maximal activity required both Na+ and K+ at a concentration of 10 mM. The enzyme was strongly inhibited by p-chloromercuribenzoic acid, and by most bivalent metal ions. Hydrolytic activity using 20 mM lactose as substrate was significantly inhibited by 10 mM galactose. The Km and Vmax values for ONPG and lactose were 2.6 mM, 262 U/mg, and 73.8 mM, 1.28 U/mg, respectively. / The objectives of this research were to characterize beta-galactosidases of B. infantis HL96 at the molecular and biochemical levels, and to over-express the enzymes in Escherichia coli. Two beta-galactosidase isoenzymes with unique properties were genetically characterized for the first time. beta-GalI properties included a neutral pH optimum, relatively higher temperature stability and a high transgalactosylic activity that makes it very competitive for GaOS synthesis. The results were also important for the advancement of knowledge on the catalytic mechanism and the evolutionary aspect of this enzyme.

Genetic transformation is a useful tool to incorporate novel genes, potentially allowing sexual incompatibility and interspecific barriers to be circumvented. The purpose of this study was to improve beta-carotene levels in melon fruits by transferring a phytoene synthase (PSY) gene. At present, there are not sufficient regeneration and transformation studies reported on two commercially important melon types - western shipper cantaloupe and honeydew. To establish a high efficiency shoot regeneration system, we evaluated three types of explants in our elite breeding lines. A shoot tip with a hypocotyl and cotyledon fragments, regenerated shoots whereas a shoot tip with a hypocotyl without cotyledon, did not produce regenerants. Murashige & Skoog (MS) basal medium with 1 mg 1⁻¹ benzyladenine (BA), 0.26 mg 1⁻¹ abscisic acid (ABA) and 0.8 mg 1⁻¹ indole-3-acetic acid (IAA) was the best for regeneration from cotyledon explants in cantaloupe 'F39'. MS basal medium with 1 mg 1⁻¹ BA and 0.26 mg 1⁻¹ ABA was chosen for honeydew '150' to solve a curving-up problem of explants. Fifty to sixty percent of regenerants were found to be polyploids. To establish a reliable Agrobacterium-mediated transformation protocol, kanamycin sensitivity as well as Timentin[trademark] and Clavamox® were evaluated. Kanamycin 200 and 150 mg 1⁻¹ were chosen as the threshold levels for 'F39' and '150' respectively. No significant differences were found between Timentin[trademark] and Clavamox® in 'F39'; however, Clavamox® reduced the incidence of vitrification and increased the frequency of shoot elongation in '150'. A. tumefaciens strain EHA105, harboring pCNL56 carrying nptII and gusA genes, was used to establish a transformation protocol. The transformation efficiency was 0.3% from 'F39' and 0.5% from '150'. We introduced a watermelon PSY-C gene under the control of a fruit-specific promoter of a polygalacturonase gene into '150'. All the transgenic plants were tetraploids based on flow cytometry assays. Up to 32-fold of beta-carotene was elevated in the rind tissue of transgenic honeydew including phytoene increase. This is a very promising result for a further investigation to increase beta-carotene level in flesh tissue using the PSY-C gene with an appropriate promoter.

No description available.

No description available.

The viscous properties of oat beta-glucan in the gut are influenced not only by beta-glucan content, but also solubility and molecular weight. The objective of this study was to determine the effects of oat processing, genotype and growing location on the physicochemical properties of beta-glucan. Five oat genotypes (HiFi, Leggett, CDC Dancer, Marion and CDC Morrison) grown in two locations (Saskatoon and Kernen) were dehulled (untreated) and processed in a pilot facility through kilning (kilned/not flaked) and subsequent steaming and flaking (kilned/flaked). Three oat genotypes (HiFi, Leggett and Furlong) went through a commercial processing including dehulling, kilning and steaming and flaking. Both pilot and commercial scale processing, genotype and growing environment had significant effects on viscosity, molecular weight and solubility of beta-glucan. Results indicate that there is potential for processors to improve the physicochemical/nutritional properties of oat end products through processing of specific oat genotypes from selected growing locations.

I dagsläget finns det en hel del kosttillskott som lovar bättre prestation, men många av substraten har inte tillräckligt med forskning bakom dem som bevisar att de verkligen fungerar. Tre av de kosttillskotten där det finns mycket forskning på och har visat sig förbättra prestationen är kreatin, koffein och natriumbikarbonat. Nyare forskning har studerat supplementering av beta-alanin som tros kan fördröja muskeltröttheten under fysisk aktivitet. Det är inte mycket av denna forskning gjord på överkroppen hos elitidrottare, därför ska detta undersökas i denna studie. Många teorier om muskeltrötthet involverar att vätejoner (H+) som härrör från bl.a. laktat, ändrar pH-värdet i muskeln, vilket kan vara en av anledningarna till varför prestationen minskar. Beta-alaninsupplementering ökar karnosin nivåerna i muskeln vilket fungerar som en H+ buffert och kan motverka sänkningen av pH-värdet i muskeln och kanske därför kan fördröja muskeltröttheten. Syftet med denna studie var att se om fyra veckors beta-alaninsupplementering kan förbättra prestationen hos högintensividrottare. Testpersonerna delades upp i två grupper, en grupp som fick beta-alanin (n=6) och en placebogrupp (n=4) som fick maltodextrin 2,5 g 2 gånger om dagen. Testet som utfördes var ett modifierat wingatetest för överkroppen, det utfördes för- och eftertester. Även blodlaktat testades direkt efter utfört test samt 2 minuter efteråt. Testet resulterade inte i några statistiska signifikanta skillnader i average power och peak power varken hos gruppen med beta-alanin eller placebo (p≥0,13). Eftertesterna visade ett högre värde av blodlaktatet 2 min efter avslutat test i jämförelse med förtesterna i beta-alaningruppen (p=0,05). Slutsatsen av denna studie var att vi inte kunde visa att 4 veckors beta-alaninsupplementering leder till bättre prestation i överkroppen hos tränade individer i den utförda interventionen, större studier bör utföras.

Bakgrund: Idag finns det en stor marknad som enbart fokuserar sig på kostillskott, vars uppgift är att få styrketränande människor att prestera maximalt. Många sätter idag sin tro på de preparat som säljs i kostillskottsbutiker, detta medför att försäljningen av kosttillskott under de senaste åren har ökat explosionsartat runt om i världen, inte minst i Sverige. Syfte: Syftet med denna studie är att undersöka friska, fysiskt aktiva mäns styrka, muskulära uthållighet och deras mentala tillstånd vid konsumtion av prestationshöjande preparat (PWO) med ingredienserna koffein, beta-alanin, kreatin, och L-arginin. Metod: Denna studie använde en randomiserad, dubbelblind, placebokontrollerad studiedesign där 18 fullt friska, fysiskt aktiva män deltog. Testpersonerna utförde styrketester, uthållighetstester samt tester gällande deras mentala tillstånd vid intag av PWO och placebo (PL). Testresultaten analyserades sedan i SPSS.  Resultat: Bänkpressen samt uthållighetstestet påvisade ingen signifikant skillnad (p=0,362), (p=0,195). Styrketestet i knäböj visade däremot en signifikant skillnad mellan PWO och PL (Placebo) där deltagarana presterade bättre efter PWO (p=0,007). Den mentala energinivån visade ingen signifikant skillnad mellan PWO och PL (P=0,340). PWO visade dock på en signifikant förbättring av trötthetsnivå, (P=0,002), vakenhetsnivå (P=0,003) och fokuseringsnivå (P=0,002). Diskussion: Om nu PWO till förstone är anpassat och framför allt används av personer med en tydlig träningsinriktning i egenskap av att öka styrka. Prestationsökningen är något som är viktigt för inte bara personer som tränar utan även för dem som antigen rehab-tränar eller för dem som, av olika anledningar, ordineras träning av läkare. Frågan är om PWO kan användas på annat sätt än enbart för gymintresserade personer? Slutsats: PWO har en effekt att den möjliggör en förbättring av träningsresultaten på friska styrketränande individer 24 år ± 4 år

This thesis assessed the prevalence, patterns of antibiotic resistance, and molecular characteristics of ESBL-, AmpC-, and carbapenemase-producing Escherichia coli (EC) and Klebsiella pneumoniae (KPN) isolated from Canadian hospitals. Bacterial isolates were collected as part of the CANWARD national surveillance study. The prevalence of ESBL-EC [2007: 3.4%, 2012: 7.6%], AmpC-EC [2007: 0.7%, 2012: 2.2%], and ESBL-KPN [2007: 1.5%, 2012: 3.6%] increased between 2007 and 2012. Antimicrobials demonstrating the greatest activity against isolates in this study were colistin, amikacin, ertapenem, and meropenem, while 78.8%, 34.9%, and 66.7% of ESBL-EC, AmpC-EC, and ESBL-KPN, respectively, were multidrug resistant. Isolates were generally unrelated by PFGE; however, ST-131 was identified among 56.9% and 31.7% of ESBL-EC and AmpC-EC, respectively. CTX-M-15 was the dominant genotype in ESBL-EC (66.5%) and ESBL-KPN (48.1%), while the dominant genotype in AmpC-EC was CMY-2 (53.2%). Carbapenemase production was identified in 0.03% of EC and 0.05% of KPN, all of which produced KPC-3.

In part one, betulinic acid (1) was isolated from the American Sycamore (Platanus occidentalis) in 1.6% yield, while ursolic acid (3) was isolated from Fuji and McIntosh apple peels in 1.0% and 0.8% crude yields, respectively. Oleanolic (4) and dehydrocanophyllic (6) acids were previously available, along with several analogs. Additional analogs of 1, 3 and 4 were prepared, including 9 new compounds, for a total of 51 compounds. Compounds were initially screened for cortisol lowering properties in vitro using a fish head kidney cell assay. Platanic acid (43) was selected for in vivo study in rats, along with 1 and a blend of Platanus occidentalis and Souroubea sympetela. No significant cortisol lowering was observed in vivo. In part two, β-ionone-d6 (75) was synthesized in 6.5% yield from ethyl 2-oxo-cyclohexane carboxylate (77). Total deuterium incorporation was 99.85%, with 0.03% d0 analog. 75 was converted to retinoic acid-d6 (93) in 2.2% yield.